Modifying the array in-place while iterating over its keys can lead to incorrect results and data loss. If a key is replaced with a name that exists later in the original array, the value associated with that new key will be overwritten before it is processed. Furthermore, the loop will eventually reach that new key and process the already-replaced value a second time.

To fix this, consider building a new array for the transformed data instead of modifying $data in-place. This ensures each original key-value pair is processed exactly once and correctly handles scenarios like key swaps.

Example fix:

$new_data = [];
foreach ( $data as $key => $value ) {
    $new_value = $this->run_recursively( $value, false, $recursion_level + 1, $visited_data );
    $new_key   = $key;
    if ( $this->replace_keys && is_string( $key ) ) {
        $new_key = $this->run_recursively( $key, false, $recursion_level + 1, $visited_data );
    }
    $new_data[ $new_key ] = $new_value;
}
$data = $new_data;

The addition of the $replace_keys parameter in the middle of the constructor's argument list is a breaking change for the SearchReplacer class's public API. Any existing code calling this constructor with positional arguments (e.g., to set $regex or $logging) will now pass those values to the wrong parameters. It is recommended to append new parameters to the end of the argument list to maintain backward compatibility.

public function __construct( $from, $to, $recurse_objects = false, $regex = false, $regex_flags = '', $regex_delimiter = '/', $logging = false, $regex_limit = -1, $replace_keys = false ) {

If the SearchReplacer constructor signature is updated to append $replace_keys at the end (to maintain backward compatibility), this call should be updated accordingly.

$replacer   = new SearchReplacer( $old, $new, $this->recurse_objects, $this->regex, $this->regex_flags, $this->regex_delimiter, false, $this->regex_limit, $this->replace_keys );

If the SearchReplacer constructor signature is updated to append $replace_keys at the end (to maintain backward compatibility), this call should be updated accordingly.

$replacer = new SearchReplacer( $old, $new, $this->recurse_objects, $this->regex, $this->regex_flags, $this->regex_delimiter, null !== $this->log_handle, $this->regex_limit, $this->replace_keys );